Emergency alert systems are widely used. One common example of such a system is the emergency broadcast system used on television and radio. This system is often used to transmit information about potentially dangerous weather conditions. Other emergency alert systems rely on land-based telephone systems to send recorded messages to all persons within a particular area. Evacuation orders are another form of an emergency alert message, and these orders may rely on telephone systems, door-to-door communication by law enforcement officers, and other emergency communication methods.
As the public has become more concerned about terrorism threats and as communication systems have become more pervasive, a need has arisen for a better emergency alert system. Existing technologies suffer from many problems. A door-to-door communication of emergency information is effective at targeting only persons actually located in the area deemed to be at risk. Though door-to-door communication can be slow—the speed of this method depends on the number of persons to be contacted and the number of persons going door-to-door—it does provide the emergency information to the relevant members of the public. This benefit, however, comes at a very high price. Dedicating many law enforcement officers' time to going door-to-door costs a great deal of money and creates troublesome opportunity costs. If three-fourths of the local police force is going door-to-door to warn persons about an emergency situation, those officers cannot be patrolling for crimes or other problem situations. Though it is one means of geographically disseminating an emergency alert, door-to-door emergency communication is typically seen as a means of last resort.
Sirens also have been used to alert persons to emergencies. A siren system is perhaps most effective for a particular purpose. A chemical plant, for example, might use sirens to warn persons near the plant of a problem. Sirens have limited range and require regular upkeep. Sirens typically do not provide situation-specific information. Persons inside houses or in automobiles may not hear sirens even when they are relatively near the siren. The one upside to sirens is their partial geographic selectivity. Only persons within a certain radius of the siren will get the alert. Even this advantage is limited, however, because in most emergencies, the alert area will not be a perfect circle around a particular siren. For these reasons, sirens remain a generally poor means of alerting persons of an emergency.
The emergency broadcasting system (EBS) sends emergency alert messages via live television and radio feeds. Though this system can reach many persons quickly, its reach is both too broad and too narrow. It is too broad because an entire television and radio broadcast region will be covered when most emergency alerts are relevant to only some part of that region. It is too narrow because even persons who are using their televisions or stereos may not be receiving a live television or radio transmission. Television viewers may be watching a move on DVD, watching a pre-recorded television program, or viewing a satellite television broadcast. Persons listening to stereos may be listening to satellite radio or a music CD. None of these persons would receive the EBS alert.
Automated telephone calling systems are widely used for sending emergency alert messages. This system is geographically specific, because only those phones within a defined alert area will be called. There are, however, several problems with these systems. They are expensive to purchase and use. They do not reach nearly all the relevant public. Many persons miss phone calls, and most of these systems call only landline phones. That excludes all cell phones and VoIP phones. Because some numbers must be called many times to reach a person, this process also can be slow. Finally, when a telephone alert system is used, it can jam the local telephone switching network, thus slowing the system and making it very difficult for local persons to use their own phones.
Internet and e-mail also may be used to send emergency alert information. This process can work quickly, but it has limited reach. It is also not geographically limited.
Given the heightened concerns with emergency threats and the many flaws in existing emergency alert systems, there exists a need for a better system. Such a system should operate quickly and reach all persons within the appropriate geographic area. It should be affordable to own and operate. A cost-effective geographically targeted emergency alert system is needed.
The present invention provides such an emergency alert system (EAS). The invention provides a method of sending geographically-targeted emergency alert messages to emergency alert enabled devices (EAEDs) operated by end users. Only those EAEDs within the geographic area at risk are notified of the emergency. The EAEDs are small devices that may be embedded within host devices such as cell phones, automobile stereos and/or navigation systems, televisions, radios, computers, mp3 players, land-line telephones, and virtually any other host device with the capacity to communicate message content to an end user. By incorporating the EAEDs into a wide variety of hosts, the present invention creates an EAS with the potential to reach virtually all appropriate persons very quickly. It is reliable, easy to operate, fast, and is geographically selective. It also requires only routine upkeep.
In a preferred embodiment, the invention includes an emergency operations center that selects an emergency alert message and identifies a geographic area of concern; an emergency alert transmission center that transmits the emergency alert message and a geographic area message that is representative of the geographic area of concern; a satellite that receives the emergency alert message and the geographic area message and retransmits these messages back to earth; and, an emergency alert enabled device that receives the retransmitted emergency alert message and geographic area message and that presents the emergency alert message if and only if the emergency alert enabled device is located within the geographic area of concern.